fix: filter test_*.py files and pytest fixtures from optimization

[KRRT7]

Summary

• Add test_*.py prefix and conftest.py patterns to is_test_file() for the overlapping tests_root case
• Add @pytest.fixture filtering in libcst FunctionVisitor to exclude fixtures from discovery
• Add tests for both changes

Fixes test functions being optimized when tests-root = "." (e.g., test_fallback_agent.py in test_unst_prop/ directory).

Test plan

• test_filter_functions_python_test_prefix_convention — verifies test_*.py and conftest.py filtering
• test_pytest_fixture_not_discovered — verifies all forms of @pytest.fixture are excluded
• All 23 existing discovery tests pass

[claude]

PR Review Summary

Prek Checks

Fixed: 2 formatting issues resolved and pushed:

• tests/test_function_discovery.py: Inconsistent indentation on line 1210 (extra spaces before project_root=temp_dir)
• codeflash/discovery/functions_to_optimize.py: Trailing blank lines at end of file

All checks now pass (ruff check + ruff format).

Mypy

All mypy errors in the changed files are pre-existing (not introduced by this PR). The source file errors are in unchanged lines, and the test file errors (missing -> None return types) follow the same pattern as existing tests in the file.

Code Review

No critical issues found. The changes are well-structured:

• is_pytest_fixture method: Correctly handles all decorator forms (@pytest.fixture, @pytest.fixture(), @fixture, @fixture(), @pytest.fixture(scope=...)) by unwrapping cst.Call nodes before checking the underlying reference.
• is_test_file additions: Properly uses basename (not full path) to check test_* prefix, avoiding false positives on files like contest.py or directories like /home/user/tests/myproject/.
• Defense in depth: File-level filtering (conftest.py, test_*.py) catches test files early, while function-level filtering (is_pytest_fixture) handles fixtures in non-test files via the libcst path.
• Note: The AST-based FunctionWithReturnStatement visitor does not have fixture filtering, but this is acceptable since the file-level filter handles conftest.py and test files before function discovery.

Test Coverage

File	Main	PR	Change
codeflash/discovery/functions_to_optimize.py	59%	69%	+10%
tests/test_function_discovery.py	100%	100%	No change

• All new lines are covered by tests (lines 81-92 is_pytest_fixture, line 97 fixture check, lines 844-851 is_test_file additions)
• 2 new tests added: test_filter_functions_python_test_prefix_convention and test_pytest_fixture_not_discovered
• All 14 tests in test_function_discovery.py pass (12 existing + 2 new)
• Coverage increased by 10% on the modified source file

Codeflash Optimization PRs

Checked 7 open optimization PRs targeting main. All have failing CI — none eligible for merge.

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Last updated: 2026-02-12T17:30 UTC